Abstract

Detecting magnetic fields in Wolf-Rayet stars

Antoine de la Chevrotière (Université de Montréal)

Nicole St-Louis, Anthony F.J. Moffat

WR stars drive strong and dense winds resulting in a wind momentum that can reach up to 30 times the photon momentum available to drive the wind via single scattering, thus stretching to the limit any model of radiation-pressure driven winds. The presence of a magnetic field in such a stellar environment might be the cause of various interesting phenomena, e.g. abundance anomalies, non-thermal and/or X-ray emission, large-scale wind asymmetries and perhaps an additional wind-driving mechanism. Spectropolarimetry of WR stars at a high level of sensitivity will most certainly provide constraints for future modelling and thus may have major implications on our understanding of their evolution. The real challenge in this case is, in fact, to unambiguously detect the field. We present ESPaDOnS spectropolarimetric observations of WR stars obtained mostly by the MiMes collaboration. Focus will be put on one of the brightest WR stars, WR6 = HD50896 = EZ CMa, and on the challenges encountered from data reduction, to analysis, to interpretation.

Mode of presentation: poster